one of the key changes is the Schema and Context which is explained in the docs, the generators are chained and the generator with the largest scope is Mix.Tasks.Phx.Gen.Html

Generates controller, views, and bounded context for an HTML resource.

mix phx.gen.html Accounts User users name:string age:integer

The first argument is the context name followed by
the schema module and its plural name (used for resources and schema).

The above generated resource will contain:

* a context module in lib/accounts.ex, serving as the API boundary
to the resource
* a schema in lib/accounts/user.ex, with an `accounts_users` table
* a view in lib/web/views/user_view.ex
* a controller in lib/web/controllers/user_controller.ex
* a migration file for the repository
* default CRUD templates in lib/web/templates/user
* test files for generated context and controller features

another big, significant commit is fb5c340e351715ecd324d3d8ceb18b4f0c779d5a